Have you loaded a DOS driver for the specific sound card?
Have you set up the autoexec.bat and config.sys?
For the sound card to work properly in MS-DOS, the MS-DOS drivers must be downloaded and/or the autoexec.bat and config.sys must have lines specified within them. The lines in the autoexec.bat may look similar to:
SET SOUND=C:\PROGRA~1\CREATIVE\CTSND
The above line is specifying where the sound drivers are located. In the above example, this is the location of the creative labs sound card drivers.
SET BLASTER=A220 I5 D1 H5 P330 E620 T6
In the above line this is specifying the sound card settings. Below is a listing of each of the important settings and what they represent:
A220 = The Input/Output Range
I5 = Interrupt Request
D1 = Direct Memory Access
The above settings are generally always used with most sound cards. If you are unsure of your settings when configuring a sound card in a MS-DOS game it is recommended you try the above three settings first.